- #1

lioric

- 306

- 20

**Plz could you check this working for me??**

## Homework Statement

Two blocks, A and B (with mass 50 kg and 100 kg, respectively), are connected by a string, as

shown in figure.

The pulley is frictionless and of negligible mass. The coefficient of kinetic friction between

block A and the incline is μk = 0.25. Determine the change in the kinetic energy of block A as

it moves from (C) to (D), a distance of 20 m up the incline (and block B drops down a

distance of 20 m) if the system starts from rest.

## Homework Equations

Block A

T-μR+mg sinθ= ma

Block B

mg-T=ma

## The Attempt at a Solution

acceleration in both blocks is the same since they are connected directly with no elastic strings

Block A

T=ma+μR-mg sinθ

Block B

T=mg-ma

Substitute for T

mg-ma=ma+μR-mg sinθ

(100 x 9.8) - (100a) = (50a) + (0.25 x 50 x 9.8 x cos 37) - (50 x 9.8 x sin 37)

980-100a-50a=97.83-294.89

-100a-50a=97.83-294.89-980

-150a=-1177.057

a=7.8

is this correct?